The figure shows how to couple two TTL circuits using an optical coupler to obtain isolation. The circuit is shown in the August 1992 issue of Radio Electronics magazine.
Using the CMOS 4001 we found this circuit in the October 1974 Radio Electronics magazine. The...
One 4018 is used to divide the frequency of a digital signal by ten as shown here. The maximum...
This 90's project shows how to use an old cassette recorder to practice telegraphy. In position A of the...